there's no such thing as a genuinely random number in this sense. or at least that's my two penn'th. isn't there some quote about if you want a random number generator then you'd better make sure that the numbers aren't picked "randomly"?

you could hypothesis test a sample, say on the assumption they are uniformly chosen from the interval [0,1] i suppose, though why is this in calculus?

Digital computers are deterministic. Consequently, the typical answer is that people use pseudo-random number generators. There is actually a good bit of theory that goes into them. Knuth is (as usual) excellent on this topic. I think it's volume two of the art of programming and covers designing and test PRNG algorithms.

Quantum physics suggests that there are techniques, for example certain types of two slit experiments, that generate truly random numbers.

What I do to get rid of the pseudo-randomness as much as possible is this...
When writing a program or whatever, I'll make several loops that randomly generate a seed value for my random number generator, then generate the number. After looping this 100 times, I've at least arrived at a number that is more random than a pseudo random, but still isn't perfectly random..

hmm.. what's that called when you have a phrase like "pretty ugly"? that "perfectly random" kinda seems that way.

There are some random number generators that attempt to generate numbers not from some prescribed formula, but by using noise coming from computer parts (like the sound card). I don't know the specifics, but you can imagine that would be comparably better. If you browse around the web, you might find some source files that would let you get a hold of those kind of numbers inside a program.